Drain control system for a washing machine



J. E. EGLE March 10, 1964 DRAIN CONTROL SYSTEM FOR A WASHING MACHINE Filed 001;. 29, 1962 2 Sheets-Sheet 1 F'IGJ INVENTOR. JOHN a. 605. Q

H ATTORNEY March 10, 1964 I .1. E. EGLE DRAIN CONTROL SYSTEM FOR A WASHING MACHINE Filed Oct. 29, 1962 2 Sheets-Sheet 2 F'IG.3

DRA'IN DRAIN DRAW DRAIN H 1 s ATTORNEY United States Patent 3,124,145 DRAIN CONTROL SYSTEM FOR A WASHING MACHINE John E. Egle, Georgetown, Ind., assignor to General Electric Company, a corporation of New York Filed Get. 29, 1962, Ser. No. 233,682 3 Claims. (Cl. 134-57) This invention relates to control systems for washing machines, and more particularly to an improved arrangement, for use primarily in dishwashers, to prevent occurrence of the undesirable noise which results from operation of the drain pump after substantially all the liquid has been drained out of the machine.

It is an object of my invention to machine in which, after a vided, the forced drain out operation will be provided only as long as there is need for it and will be followed immediately by whatever subsequent operation is desired, as soon as all vitiated liquid has been removed.

The present invention is an improvement over the device disclosed in the copending application of Thomas E. Jenkins and Melvin R. Kaufiman, Serial No. 233,683, filed October 29, 1962 and assigned to the assignee of the present invention, in that the present invention provides immediate follow up by whatever subsequent operation is desired upon removal of substantially all the liquid in the machine.

In one aspect of my invention, I provide a washing machine of the type which has an automatic washing cyle. In the usual way, the machine has a tub, washing means for washing articles in the tub, and a drain pump for removing vitiated liquid from the tub toether with a drain conduit connected to the pump. Suitable sequence control means are provided for causing operation of the washing means and then operation of the pump, the sequence control means being eifective to cause these operations to be repeated a predetermined number of times.

The sequence control means includes an electric timer motor which drives a plurality of cam means so as to operate several switches. The first of these switches enables completion of the timer circuit for energizing the timer motor, while a second of these switches enables completion of a pump circuit for causing operation of the drain pump. Together with this structure, I provide flow responsive means for sensing flow through the drain conduit and for operating a third switch in response to flow therethrough. This third switch has a normal position which enables completion of the first circuit, but is moved to a second position whenever there is flow through the drain conduit. In its second position, the third switch prevents completion of the first circuit notwithstanding the first switch. The sequence control means closes the second switch to start operation of the pump, and opens the second switch when the timer motor is re-energized after flow through the drain-conduit stops. As a result, the drain out operation is primarily under the control of the flow responsive means which, as soon as it senses that flow through the drain conduit has stopped, permits the ensuing operation to be commenced.

In the drawings, FIGURE 1 is a side elevational view, with some of the parts broken away to illustrate details, of a dishwasher incorporating my invention;

FIGURE 2 is an enlarged view in cross section showing part of the structure of FIGURE 1 FIGURE 3 is a schematic electric wiring diagram showing my improved control system in one form thereof; and

FIGURE 4 is a sequence control cam chart illustrating the sequence of operation of the schematically shown switches of FIGURE 3.

provide a washing washing operation is pro- 3,124,145 Patented Mar. 10, 1964 Referring now to FIGURE 1, there is shown for illustrative purposes a portable automatic dishwasher 1, although my invention will be understood to apply equally well to built-in machines. The dishwasher has a dishwashing compartment 2 formed by a tub 3 with a top opening 4 adapted to be closed by a cover 5 hingedly mounted at the rear of the machine by an assembly 6. The bottom of the tub may have a downwardly sloped portion 7 forming a sump at the center thereof. Tub 3 may have side walls which continue down almost to the base or the floor on which the machine rests so as to form an enclosure or cabinet for the machine. Also, these walls may support casters 8 in any conventional manner so as to make the machine movable.

Within compartment 2 there may be provided a number of dish supporting members such as an upper rack 9 and a lower rack 10 which are designed so as to sup port dishes and other eating and cooking utensils. Dishwasher 1 incorporates suitable washing means which in this case is embodied in a rotatable water ejecting member 11 positioned below rack 10 together with a telescoping member 12 positioned at the center of member 11. When under pressure, member 12 rises somewhat and is provided with apertures in its top so as to eject water with substantial force against dishes in the upper rack 9. At the same time, member 11 is rotating under the force of the water and is ejecting that water against the dishes in both racks.

Arm 11 and telescoping member 12 form a part of an assembly 13 which further includes a motor 14. M0- tor 14 operates a pumping assembly 15 which may be of conventional design and which receives its water through an inlet 16 at the very bottom of sump 7. The motor may be of the type which, when rotated in one direction, causes the pumping assembly to force liquid up through members 11 and 12, and which when reversed causes the pumping assembly to act as a drain pump and pass the liquid out to drain, such structures being commercially available and well known to those skilled in the art.

In addition, for drying the dishes after they have been cleansed, a suitable electric heating element 17 may be provided in the conventional manner. The heating element 17, as well as the motor 14- and the conventional water inlet valve (not shown in FIGURE 1) will normally be under the control of a sequence control assembly (also not physically shown in FIGURE 1). The assembly may be secured within the hollow front wall 18 of the dishwasher, with suitable manually operable members such as 1 extending up so as to be readily accessible to an operator for the selection of a sequence of operations of the machine. A suitable sequence of operations of the machine is described in connection with FIG- URES 3 and 4 herebelow.

It will be understood that all the components described thus far are conventional and are provided in dishwashers widely available for purchase by the public.

Connected to the outlet 20 of pump 15, and leading to a drain, is a drain conduit 21 to which there is secured an assembly 22. Referring particularly to FIG- URE 2, it can be seen that assembly 22 includes a switch 23 having an operating member or button 24 against which is a diaphragm 25 having a surface 26 constituting a part of the wall of conduit 21. When there is no flow through conduit 21, the button is in its extended position as shown, and the switch 23 has a first position for a purpose to be hereinafter discussed. However, when liquid flow occurs through conduit 21 as a result of a drain operation, then pressure of that flow causes the diaphragm 25 to move so as to depress button 24 and operate the switch 23.

Referring now to FIGURE 3, there is shown a control circuit embodying my invention. It will be understood that, besides the components specifically shown, other electrically controlled components of the machine, such as suitable indicating lights and detergent and rinse agent dispensers, will often be controlled electrically. These other components have been left out of FIGURE 2 only in order to show clearly the invention without confusing additional details which do not form a part thereof.

The circuit is energized through a pair of supply conductors 27 and 28 across a suitable source of power (not shown) such as the conventional 110* volt 60 cycle source generally available. Connected across the conductors 27 and 28 is the timer motor 29 of the sequence control assembly previously referred to. As shown schematically in FIGURE 3, this sequence control assembly includes the motor 29 in controlling relationship to a plurality of cams 30, 31, 32, 33 and 34, with the cams 30-34 in turn being in controlling relationship to switches 35, 36, 37, 38 and 39. In addition, the assembly will normally include the manual control members previously referred to by the numeral 19 in FIGURE 1. Switch 35 is in series with motor 29 across the conductors 27 and 28 so as to permit energization of the motor 29 when it is closed and prevent energization thereof when it is opened. Similarly, the heating element 17 is connected across conductors 27 and 28 in series with switch 36, and a solenoid 40 controlling the water valve of the machine is connected across conductors 27 and 28 in series with the switch 37.

The motor 14 includes a main winding 41 and a pair of start windings 42 and 43. When winding 41 and winding 42 are energized at the same time, the motor starts to rotate in the direction appropriate to cause operation of the washing structures 11 and 12. When windings 41 and 43 are energized at the same time the motor starts to rotate in the direction eifective to make pump 15 drain liquid out of tub 3 through conduit 21. In the conventional manner, the start relay 44 may be provided in series with the winding 41, in controlling relationship to a contact 45 in series with both windings 42 and 43. At a relatively high current level, such as that which flows through the relay 44 when the motor is not rotating, relay 44 closes switch 45. As the motor comes up to speed, the level of energization drops substantially; as a result, relay 44 lets switch 45 move to its normally open position to insure de-energization of whichever of windings 42 and 43 was energized. Thus, the motor 14 may be caused to start in either direction of rotation, as will be explained, and will then continue to run on the winding 41 alone after it comes up to speed.

The direction of rotation is determined by switch 39 which is movable into engagement with either of two contacts 46 and 47 to provide for selection of start windings 42 or 43 respectively. Both the start windings, through switch 39, and the main winding are connected through switch 38 so that the entire motor energizing circuit is connected across lines 27 and 28 and is controlled by switch 38.

Switch 23 includes a contact arm 49. In the normal position of the switch, that is, when there is no flow through conduit 21, contact arm 49 is closed. Contact arm 49 of switch '23 is connected in series both with switch 35 and with motor 29, i.e., in the energizing circuit for motor 29. This causes it to be effective to control the timer motor energizing circuit across lines 27 and 28. When contact arm 49 is open the motor 29 is deenergized regardless of the position of switch 35; the converse, or course, is also true, that is, opening switch 35 will de-energize the timer motor independently of the position of contact arm 49.

Referring now to FIGURE 4, it will be seen that it is intended that a conventional sequence of operations of the machine includes a first rinse which actually is introduction of water and a brief washing operation; this may either be with or without detergent, and is followed by draining of that water. A second similar rinse and drain are then provided, followed by a is simply a provision of the washing operation for a longer period of time with, preferably, a suitable detergent being injected. This wash is then again followed by drain and then two rinses and drains follow, after which a drying operation may be provided. This is a typical sequence of operations for a dishwasher.

One difficulty that has been encountered to date is that, with machines that have been on the market thus far, the draining operation has been provided for a predetermined period of time. The water is removed from the machine prior to the end of that time and this results, with many types of pumping structures, in a noise which may be objectionable to some extent to the operator. It is an important aspect of my invention that operation of the drain pump after the liquid has been removed is immediately terminated and the subsequent operation, either the following rinse, or the dry operation, or whatever is intended to follow the draining of the liquid is promptly started. Thus, my invention is intended to provide two advantages: first, it prevents any possibility that the objectionable noise referred to above may exist; and second, it minimizes the length of time for a cycle in that the drain part of the cycle of the machine is no longer than is necessary to remove all liquid.

In order to achieve this, the timer operated switch 38, which normally controls motor operation, is caused to open at the end of the first rinse, as can be seen in FIG- URE 4, as a result of the surface configuration of cam 33. This causes the motor 14 to be de-energized, and during this de-energization, as shown by the contour of cam '34, switch 39 reverses its position.

As a result, when switch '38 is re-closed very soon thereafter, the motor is re-energized, but in the opposite direction to the direction in which it rotated during rinse. As previously described, the structure is one in which the motor provides operation of the washing means 11 and 12 when it rotates in one direction, but operation of pump 15 as a drain pump during rotation in the opposite direction. Thus, because of the moving of switch 39 from engagement with contact 46 to engagement with contact 47, motor 14 starts up in a direction to effect removal of liquid through conduit 21 when switch 38 is re-closed.

Because of the flow of vitiated liquid through conduit 21 resulting from this operation of motor 14, the diaphragm 25 has caused switch 23 to move away from its normal position. In other words, contact arm 49 has been opened. The opening of contact arm 49 stops the timer motor so that the cams cease to be rotated. This state of affairs continues until all the liquid in tub 3 has been removed through conduit 21 by pump 15. At this point, when there is no further liquid being pumped through the conduit, the pressure on diaphragm 25 is relieved and the switch 23 is returned to its normal position in which contact arm 49 is closed. The reclosing of contact arm 49, as a result of the return of switch 23 to its normal position, causes the timer motor circuit to be completed again and the timer motor is energized thereby starting rotation of the cams once again. This rotation of the cams promptly causes opening of switch 38 and reversal of the position of switch 39 so that it is once again in engagement with contact 46, followed by a reclosing of switch 38. This causes a rinse operation to be provided again, it being seen from FIGURE 4 that appropriate closing of switch 37 is also provided at this point. Thus, the second rinse operation is actually provided in response to the removal of all vitiated liquid from the first rinse operation. The drain pump operates no longer than necessary, and the fact that the drain pump has ceased to pump fluid has the second, and also important, effect of causing the subsequent rinse step to be promptly commenced.

As can be seen in FIGURE 4, the second rinse operation is provided and then cams 33 and 34 again provide the particular sequence described in order to achieve a wash step which drain operation limited in time to that necessary for removal of liquid. It will be observed that this particular sequence is followed for each drain operation, with the fifth or last drain operation then being followed by a drying operation achieved by closure of switch 36.

It will be seen from the foregoing that my invention provides a control arrangement which insures both that operation of the drain pump will continue only as long as there is liquid to be drained, and that the next operation after the draining operation will be started promptly in response to the removal of all the liquid.

While in accordance with the patent statutes I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein Without departing from the invention, and I therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A Washing machine for providing an automatic washing cycle comprising:

(a) a tub;

(b) washing means arranged to effect Washing of articles in said tub;

(c) a drain pump for removing vitiated said tub;

(d) a drain conduit connected to said pump;

(e) sequence control means for causing operation of said washing means and then operation of said pump, said sequence control means being effective to cause said operations to be repeated a predetermined number of times;

(1) said sequence control means including an electric timer motor, first and second cam means driven by said motor, and first and second switches controlled by said first and second cam means;

(g) a timer circuit for energizing said timer motor, said first switch enabling completion of said timer circuit;

(11) a pump circuit for causing operation of said pump, said second switch enabling completion of said pump circuit; and

(i) flow responsive means for sensing flow through said drain conduit including a third switch, said third switch having a normal position enabling completion of said timer circuit, said third switch being moved to a second position as long as there is fiow through said drain conduit in which it prevents completion of said first circuit notwithstanding said first switch;

(i) said second cam means being configurated to promptly open said second switch upon reenergization of said timer motor.

2. The apparatus defined in claim 1 wherein said flow responsive means comprises a diaphragm forming part of the wall of said drain conduit, said diaphragm being in operating relationship to said third switch thereby liquid from to move said third switch from its normal position to its second position upon deformation of said diaphragm by flow through said drain conduit.

3. A washing machine for providing an automatic washing cycle comprising:

(a) a tub;

([2) Washing means arranged to eflect washing of articles in said tub;

(c) a drain pump for removing vitiated liquid from said tub;

(d) a drain conduit connected to said pump;

(e) motor means for operating said washing means and said drain pump;

(1) sequence control means for causing said motor means to selectively operate either said drain pump or said washing means, said sequence control means causing operation of said washing means and then operation of said pump, said sequence control means being elfective to cause said operations to be repeated a predetermined number of times;

(g) said sequence control means including an electric timer motor, first and second cam means driven by said timer motor, and first and second switches controlled by said first and second cam means;

(11) a timer circuit for energizing said timer motor, said first switch enabling completion of said timer circuit;

(i) a first motor means circuit for causing operation of said washing means, said second switch having a first position enabling completion of said first motor means circuit;

(j) a second motor means circuit for causing operation of said pump, said second switch having a second position enabling completion of said second motor means circuit; and

(k) flow responsive means for sensing flow through said drain conduit including a third switch, said third switch having a normal position enabling completion of said timer circuit, said third switch being moved to a second position as long as there is flow through said drain conduit in which it prevents com pletion of said timer circuit notwithstanding said first switch;

(I) said second cam means being configurated to promtly move said second switch to its first position upon re-energization of said timer motor.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Jenkins et al., S.N. 233,683, filed Oct. 29, 1962.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 124 145 March 10 1964 John E, Egle It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5 line 51, for "first" first occurrence read me timer Signed and sealed this 7th day of July 1964 (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A WASHING MACHINE FOR PROVIDING AN AUTOMATIC WASHING CYCLE COMPRISING: (A) A TUB; (B) WASHING MEANS ARRANGED TO EFFECT WASHING OF ARTICLES IN SAID TUB; (C) A DRAIN PUMP FOR REMOVING VITIATED LIQUID FROM SAID TUB; (D) A DRAIN CONDUIT CONNECTED TO SAID PUMP; (E) SEQUENCE CONTROL MEANS FOR CAUSING OPERATION OF SAID WASHING MEANS AND THEN OPERATION OF SAID PUMP, SAID SEQUENCE CONTROL MEANS BEING EFFECTIVE TO CAUSE SAID OPERATIONS TO BE REPEATED A PREDETERMINED NUMBER OF TIMES; (F) SAID SEQUENCE CONTROL MEANS INCLUDING AN ELECTRIC TIMER MOTOR, FIRST AND SECOND CAM MEANS DRIVEN BY SAID MOTOR, AND FIRST AND SECOND SWITCHES CONTROLLED BY SAID FIRST AND SECOND CAM MEANS; (G) A TIMER CIRCUIT FOR ENERGIZING SAID TIMER MOTOR, SAID FIRST SWITCH ENABLING COMPLETION OF SAID TIMER CIRCUIT; (H) A PUMP CIRCUIT FOR CAUSING OPERATION OF SAID PUMP, SAID SECOND SWITCH ENABLING COMPLETION OF SAID PUMP CIRCUIT; AND (I) FLOW RESPONSIVE MEANS FOR SENSING FLOW THROUGH SAID DRAIN CONDUIT INCLUDING A THIRD SWITCH, SAID THIRD SWITCH HAVING A NORMAL POSITION ENABLING COMPLETION OF SAID TIMER CIRCUIT, SAID THIRD SWITCH BEING MOVED TO A SECOND POSITION AS LONG AS THERE IS FLOW THROUGH SAID DRAIN CONDUIT IN WHICH IT PREVENTS COMPLETION OF SAID FIRST CIRCUIT NOTWITHSTANDING SAID FIRST SWITCH; (J) SAID SECOND CAM MEANS BEING CONFIGURATED TO PROMPTLY OPEN SAID SECOND SWITCH UPON REENERGIZATION OF SAID TIMER MOTOR. 